In-vivo measuring systems are known in the art. Some in-vivo devices/systems that traverse the gastrointestinal (GI) system may include one or more imaging sensors, for imaging (e.g., capturing images of) the interior of the GI system, and/or sensors of other types. In-vivo devices may traverse the GI system by being pushed through the GI system by peristaltic force exerted by the digestive system, or by being maneuvered (e.g., magnetically). Some applications require knowing the current location and/or current orientation of the involved in-vivo device. For example, in order to magnetically maneuver an in-vivo device, for example in the GI system, the magnetic maneuvering system has to know the current location/orientation (and the target location/orientation) of the in-vivo device in order to generate the correct steering magnetic fields. Therefore, a localization system is also used to provide localization information to the magnetic maneuvering system, based on which the magnetic maneuvering system can maneuver the in-vivo device. A localization system may generate an alternating current (“AC”) electromagnetic field that may be sensed by electromagnetic field sensors that are mounted in the in-vivo device. The location and/orientation of the in-vivo device may be derived from the AC signals that the electromagnetic field sensors output.
An advanced maneuvering system may use an AC electromagnetic field and a direct current (“DC”) electromagnetic field to maneuver devices in vivo. Operating an electromagnetic based localization system and an electromagnetic based maneuvering system at the same time results in mutual interference between the two systems. For example, an external maneuvering AC magnetic field generated by the maneuvering system may have a negative side effect on the readout of the localization electromagnetic field sensors of the in-vivo device, and the external AC localization signal generated by the localization system may have a negative side effect on the maneuvering force that maneuvers the in-vivo device. Therefore, it is preferable that the two systems operate intermittently, with one system (e.g., the maneuvering system) operated while the other system (e.g., electromagnetic based localization system) is temporarily disabled, and vice versa. However, due to the high currents that are required to generate maneuvering electromagnetic fields, the electromagnetic field, which may be generated by using a switching technique, may not be able to be shut down completely in time in, and for, the required time (e.g., when the localization sensing takes place). Inability to shut down the maneuvering electromagnetic field completely may result in a residual electromagnetic field that results in erroneous determination of the location of the in-vivo device.
Therefore, it would be beneficial to have methods that would enable a magnetic maneuvering system to steer an in-vivo device, and a magnetic localization system to locate the in-vivo device without the maneuvering system interfering with the operation of the localization system. While using the maneuvering field is beneficial, in general, from the maneuvering system's standpoint, it would be beneficial to have a (localization) system that can cancel out, or significantly reduce, the electromagnetic interference caused by such residual maneuvering fields.